The Pentagon has confirmed the United States is now flying armed, unmanned drones over southern Iraq, giving American officials a quick response capability if Iraqi missiles or other targets are detected.

Confirmation of the first-ever deployment of armed Predator surveillance planes over southern Iraq comes from the top U.S. military officer.

General Richard Myers, chairman of the Joint Chiefs of Staff of the armed forces, says these unmanned drones, equipped with two Hellfire missiles each, give U.S. forces patrolling the no-fly zone a new advantage.

"It's persistent. It's over the target area for long periods of time and it can move between targets," he said. "That's the first advantage. And then it can be present while [manned] aircraft are patrolling and perhaps see with its sensors reactions to the aircraft that are flying over, whether its surface to air missiles or anti-aircraft fire, and of course then it can respond."

The Hellfire missiles carried by some Predators have relatively small warheads. But General Myers says against certain targets these are effective. The air-to-ground Hellfire has been used in the past by attack helicopters to strike armored vehicles.

General Myers gives no further details. Other Pentagon officials remain reluctant to discuss use of the armed version of the surveillance plane.

But defense sources say armed Predators patrolling over southern Iraq have already fired on at least two air defense targets, the same sorts of targets regularly struck by piloted coalition aircraft patrolling the no-fly zone.

The difference, these sources say, is that unlike the manned aircraft which do not patrol daily and whose flying time is limited, the Predators can loiter over the zone for as long as 24 hours, thus increasing the chances of U.S. officials detecting the movement of Iraqi mobile missiles or radars.

Armed Predators were first used in Afghanistan in the hunt for al-Qaida and Taleban terrorist leaders.

Most Predators are unarmed and used strictly for reconnaissance missions. These unarmed drones have been used over Iraq for some time and military officials have reported repeated unsuccessful efforts by Iraqi forces to shoot them down.